摘要
从恒化富集培养物中分离到一株产肌酸酶的菌株WB1 ,通过对该菌的形态学、生理生化特性、G +Cmol%及 1 6SrDNA序列分析 ,表明该菌为一株副球菌 (Paracoccussp .)。对菌株WB1产酶发酵条件的研究表明 ,该菌除了产生肌酸酶外还产生肌氨酸脱氢酶 ,但不产生肌酸酐酶 ,也不能利用肌酸酐。肌酸酶可以被诱导物 ,如肌氨酸、肌酸、和氯化胆碱诱导产生。葡萄糖等易用碳源的存在对肌酸酶的合成无代谢产物阻遏作用。该酶的分子量为4 8kD ,最适反应pH为 7 0~ 8 5 ,pH稳定范围在 6 0~ 9 5之间 ;其最适反应温度在 35℃~ 4 0℃之间 ,在 4 5℃以下是热稳定的 ;37℃时以肌酸为底物 ,酶的Km值为 2 4 6mmol L ;Cu2 + 、Hg2 + 和Ag+
A creatinase producing bacterium was isolated from soil with chemostat enrichment. Based on its morphological, physiological characteristics, G+C mol % of DNA and 16S rDNA sequence, it was identified as a strain of Paracoccus sp..The results of study on the fermentation conditions of strain WB1 showed that beside of creatinase, the strain also produced sarcosine dehydrogenase. However, it did not produce creatininase, and was unable to utilize creatinine. The creatinase was an inducible enzyme and could be induced by sarcosine, creatine, and choline chloride. The easily used carbon sources such as glucose had no catabolic repression effect on the creatinase production. The molecular weight of the enzyme was estimated to be 48kD by SDS PAGE. The enzyme was showed the maximum activity at pH 7 0~8 5 and was stable at pH 5 5~9 5 It was showed most activity at 35℃~40℃ and was stable under 45℃. The K m of the enzyme was 24 6 mmol/L with creatine as substrate at 37℃. The metal ions such as Cu 2+ , Hg 2+ and Ag + had strong inhibiting effect on the activity of the enzyme.
出处
《微生物学报》
CAS
CSCD
北大核心
2004年第1期83-87,共5页
Acta Microbiologica Sinica
基金
浙江省科技厅项目 ( 0 0 1110 2 3 3 0 1)~~